Holder for carbons used in projecting machines



May 27, 1952 J. E. MARR 2,598,006

HOLDER FOR CARBONS USED IN PROJECTING MACHINES Filed Oct. 22, 1949 //\/4/E/\/TUR JOHN f: MARR Fatented May 27, 1952 UNITED STATES PATENT OFFICE HOLDER FOR CARBONS USED IN PROJECTING MACHINES Application October 22, 1949, Serial No. 122,874

1 Claim.

This invention relates generally to the motion picture industry and particularly to a holder for carbons used in projecting machines.

The main object of this invention is to make it possible to utilize practically all of the carbon elements instead of discarding large portions of the carbon merely because they are not long enough to make a complete run.

The second object is to produce a saving of about fifty per cent of the cost of carbons.

The third object is to produce a holder or extension for the carbons which can utilize what are ordinarily waste ends of carbons.

The fourth object is to produce an inexpensive form of holder which will be easy to manufacture, low in cost and simple to apply to the carbons.

The fifth object is to hold the carbon element in axial alignment with the holder and insure a proper contact at the union of the holder and carbon.

I accomplish these and other objects in the manner set forth in the following specification as illustrated by the accompanying drawing, in which:

Fig. 1 is a perspective view of the holder and carbon showing for the purpose of simple illustration a water jacketed mount with a portion broken away in section.

Fig. 2 is a fragmentary perspective section taken along the line 2-2 in Fig. 1, showing the union of the carbon and holder and the mannor of insuring the proper contact.

Fig. 3 is a transverse section taken along the line 3-3 in Fig. 1.

Like numbers of reference refer to the same or similar parts throughout the several views.

Referring in detail to the drawing, there is shown a water jacketed mounting Ill through which extends my carbon holder H which is a pointed and hardened screw 18 of the self-tapping type. The end i5 has formed around the hole 16 a rounded recess 19 which fits the rounded end 26 of the carbon 2| The usual automatic means for maintaining the proper gap 22 between the carbons 2| and 23 is, of course, employed but it forms no part of the present invention and is not illustrated or described.

In the illustration, the difference in diameters of the holder II and carbon 2| has been magnified in order to better illustrate the invention. In practice, the holder II is only slightly smaller in diameter than the carbon 2 i.

When mounting the carbon 2| on the holder H the rounded carbon end 20 which is relatively soft is placed on the screw l8 and turned until it is firmly seated in the cup [9, producing an excellent contact. As the carbon is burned away, it is advanced automatically until the need for it is gone or until the screw I8 reaches the mating carbon 23.

I claim:

A carbon holder for use in picture projectin machines comprising a metal rod of slightly less diameter than that of the carbon to be held and having a cupped end and having a. self-tappin screw projecting from said cupped end along its axis, the outer edge of said cupped end being bevelled to form a sharp edge around the outer rim of said cup.

JOHN E. MARR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 863,674 Tone Aug. 20, 1907 1,115,027 Seabury Oct. 27, 1914 1,723,626 Kravitz et a1 Aug. 6, 1929 1,912,560 Wiles June 6, 1933 FOREIGN PATENTS Number Country Date 26,367 Great Britain Aug. 27, 1914 

